Apparatus for processing photographic films

ABSTRACT

A processing apparatus for photographic material wherein a first vessel for a supply of developing solution is followed by a second vessel for a fixing bath and the latter is followed by a third vessel for a rinse bath which, in turn, is followed by a dryer. The duct for evacuation of spent gaseous fluid from the dryer contains a heat exchanger whose coil conveys a stream of fresh water which is heated in the coil prior to entering a single additional heat exchanger in the first vessel whose coil conveys a stream of fresh water which is heated in the coil prior to entering a single additional heat exchanger in the first vessel or two additional series-connected heat exchangers which are connected in series and are respectively installed in the first and second vessels. Alternatively, the coil of the heat exchanger in the duct can discharge heated water directly into the third vessel; the apparatus then employs a pump which draws water from the third vessel and causes it to flow through a single additional heat exchanger in the first vessel or through two series-connected additional heat exchangers which are connected in series and are respectively mounted in the first and second vessels.

United States Patent Geyken et al.

[ APPARATUS FOR PROCESSING PHOTOGRAPHIC FILMS [75] Inventors: Erwin Geyken; Gerhard Schwarzmaier; Peter Dawidowitsch, all of Munich. Germany [73] Assignee: Agfa-Gevaert Aktiengesellschait,

Leverkusen, Germany [22] Filed: July 22, 1974 [21] Appl. No.: 490,296

Related US. Application Data [63] Continuation-impart of Ser. No. 393,834, Sept. 4,

1973, Pat. No. 3,832,730.

[30] Foreign Application Priority Data Sept 2, 1972 Germany 2243276 [52] US. Cl 354/299; 354/319 [51] Int. Cl. G03D 13/00 [58] Field of Search 354/299. 319-322, 354/324; 137/340; 165/66 [56] References Cited UNITED STATES PATENTS 2,621,571 12/1952 Katzen et al 354/319 X 2,910,838 11/1959 Ewing .1 354/299 X 2,965.013 12/1960 Dorionm 354/299 3,133,490 5/1964 Buck 354/299 3,349,689 10/1967 Buechner 354/299 3,613,547 10/1971 Snarr et al. v, 354/299 Primary ExaminerRichard L. Moses Attorney, Agent, or FirmMichael S. Striker (57] ABSTRACT A processing apparatus for photographic material wherein a first vessel for a supply of developing solu tion is followed by a second vessel for a fixing bath and the latter is followed by a third vessel for a rinse bath which, in turn, is followed by a dryer The duct for evacuation of spent gaseous fluid from the dryer contains a heat exchanger whose coil conveys a stream of fresh water which is heated in the coil prior to entering a single additional heat exchanger in the first vessel whose coil conveys a stream of fresh water which is heated in the coil prior to entering a single additional heat exchanger in the first vessel or two ad- 'ditional series-connected heat exchangers which are connected in series and are respectively installed in the first and second vessels. Alternatively, the coil of the heat exchanger in the duct can discharge heated water directly into the third vessel; the apparatus then employs a pump which draws water from the third vessel and causes it to flow through a single additional heat exchanger in the first vessel or through two series-connected additional heat exchangers which are connected in series and are respectively mounted in the first and second vessels.

10 Claims, 4 Drawing Figures US. Patent Nov. 25, 1975 Sheet 1 of4 3,922,701

9 1. wwwwm N l/ 1 US. Patent Nov. 25, 1975 Sheet 3 of4 3,922,701

US. Patent Nov. 25, 1975 Sheet 4 0f-! 3,922,701

Fig.4

APPARATUS FOR PROCESSING PHOTOGRAPHIC FILMS CROSS-REFERENCE TO RELATED APPLICATION This is a contination-in-part of our copending application Ser. No. 393,834 filed Sept. 4, 1973, now US. Pat. No. 3,832,730 granted Aug. 27, I974.

BACKGROUND OF THE INVENTION The present invention relates to apparatus for processing photographic films or the like, and more particularly to improvements in processing apparatus wherein successive films or analogous carriers of photosensitive material are conveyed along an elongated path extending seriatim through at least one developing or fixing bath, thereupon through a rinse bath and finally through a dryer. Still more particularly, the invention relates to improvements in means for heating'the liquid or liquids which contact the films during travel through a processing apparatus. Processing apparatus of the just outlined character are used, for example, in treatment of exposed X-ray films.

A drawback of presently known processing apparatus of the type wherein the films must pass through one or more baths which contain various chemicals and thereupon through a rinse bath and a dryer is that the apparatus must be provided with connections for hot and cold water. The connections for hot and cold water serve to deliver hot and cold water to a thermostatically controlled mixer valve which regulates the temperature of the water stream entering the processing apparatus, for example, the rinsing station. As a rule, the mixer valve is designed to insure that the temperature of water flowing to the rinsing station remains constant or .fluctuates negligibly within a narrow range. The mixer valve and the temperature regulating means therefore are expensive and bulky. Moreover, such apparatus can be used only in locations having outlets for cold and hot water.

Still further, the presently known processing apparatus fail to meet the existing and anticipated future'regulations governing the prevention of penetration of chemicals into the supply of drinking water.

SUMMARY OF THE INVENTION An object of the invention is to provide a novel and improved automatic or semi-automatic processing apparatus for X-ray films and/or other types of carriers for photosensitive material wherein the temperature of liquid agents which come into contact with films can be regulated with a necessary degree of accuracy without resorting to complex, expensive and sensitive thermostatically controlled mixer valves or the like.

Another object of the invention is to provide a processing apparatus for exposed photographic films or the like with novel and improved means for heating at least one of two or more liquid agents which contact the films during transport toward the dryer.

A further object of the invention is to provide a processing apparatus for exposed photographic films wherein the temperature of one or more liquid agents can be regulated with a requisite degree of accuracy even if the laboratory wherein the apparatus is installed does not have an outlet for hot water.

An additional object of the invention is to provide a novel and improved dryer for use in a processing apparatus of the above outlined character.

An ancillary object of the invention is to provide novel and improved means for conditioning one or more liquid agents in a processing apparatus in automatic response to introduction of exposed films into the apparatus.

A further object of the invention is to provide a pro cessing apparatus which is capable of processing large numbers of exposed films per unit of time and which is constructed and assembled in such a way that the temperature of one or more liquid agents therin does not drop appreciably in response to shorter-lasting or even longer-lasting interruptions in the operation of processing apparatus.

An additional object of the invention is to provide a processing apparatus which is constructed and assembled in such a way that it invariably prevents the penetration of deleterious chemicals into the supply of drinking water.

The invention is embodied in a processing apparatus for exposed films or analogous sheet-or web-like carriers of photosensitive material. The apparatus comprises a series of vessels each of which contains a supply of a processing liquid (such as a developing solution, a fixer and a rinse bath), a dryer, means for circulating in the dryer a heated gaseous fluid, means for transporting carriers of photosensitive material through successive vessels and thereupon through the drier, a source of unheated liquid (e.g., fresh water), and a heat exchanger which is connectable with the source of unheated liquid and is installed in (and may form part of) the dryer so that unheated liquid which is supplied by the source is heated while flowing in the first heat exchanger and is thereupon discharged into one of the vessels, preferably into the vessel containing the rinse bath. The apparatus may comprise at least one additional heat exchanger which is connected with the outlet of the first mentioned heat exchanger (i.e., the latter than does not discharge directly into a vessel) and serves to circulate heated liquid in one of the vessels so that heated liquid which is supplied by the first heat exchanger and flows through the additional heat exchanger heats the supply of liquid in the one vessel prior to being discharged by the additional heat exchangers into another vessel.

The vessel containing the additional heat exchanger may further contain thermostatically controlled heating means. Such heating means may be installed, for example, in the vessel for a developing solution which is circulated in the respective vessel by a pump or the like. The heating means is preferably located downstream of the additional heat exchanger, as considered in the direction of circulation of developing solution.

It is also within the purview of the invention to employ a first heat exchanger which is installed in the dryer and heats fresh liquid prior to discharging into a first vessel (e.g., the one which contains the rinse bath). This first vessel has an outlet which supplies liquid to an additional heat exchanger in a second vessel or to several series-connected additional heat exchangers in second, third, etc. vessels. The additional heat exchanger(s) may discharge liquid into the first vessel.

The novel features which are considered ascharacteristic of the invention are set forth in particular in the appended claims. The improved processing apparatus itself, however, both as to its construction and its mode of operation, together with additional features and advantages thereof, will be best understood upon perusal of the following detailed description of certain specific embodiments with reference to the accompanying drawing.

BRIEF DESCRIPTION OF THE DRAWING FIG. 1 is a schematic partly elcvational and partly longitudinal vertical sectional view of a processing apparatus which embodies one form of the invention;

FIG. 2 is an enlarged view of a heat exchanger in the dryer of the processing apparatus shown in FIG. 1;

FIG. 3 is a schematic partly elevational and partly longitudinal vertical sectional view of a second apparatus; and

FIG. 4 is a schematic partly elevational and partly longitudinal vertical sectional view ofa third apparatus.

DESCRIPTION OF THE PREFERRED EMBODIMENTS FIG. 1 illustrates a first processing apparatus 2 for photographic films l. The leader of an exposed film 1 which is fed into the processing apparatus 2 is engaged by two advancing rolls 3, 4 which introduce the film into a first vessel or tank 9 containing a holder or rack 5 for several sets of pairwise arranged transporting rollers 6, 7 serving to move the film along a substantially U-shaped path having a downwardly and an upwardly extending section. The tank 9 contains a supply of a de veloping solution whose upper level is determined by an overflow pipe 10 which is connected with an evacuating pipe 11. The tank 9 preferably consists of a synthetic thermoplastic material which is resistant to the corrosive influence of developing solution. The bottom wall of the tank 9 has an outlet 90 which is connected with the intake of a pump 12 serving to circulate developing solution in the tank 9. The outlet of the pump 12 is connected with an inlet 9b in the bottom wall of the tank 9.

A thermostatically controlled heating unit 30 in the bottom portion of the tank 9 serves to maintain the developing solution at a predetermined temperature. The heating unit 30 may comprise one or more rod-like heaters which are preferably adjacent to the inlet 9b in the bottom wall of the tank 9.

The outlet 90 is further connected with the evacuating pipe 11 by means of a conduit 9c which contains a normally closed shutoff valve 13. The valve 13 is opened when the pump 12 is arrested and the operator wishes to evacuate the contents of the tank 9.

The film l which leaves the tank 9 is introduced into a second vessel or tank 14 which is somewhat shallower than the tank 9. The tank 14 contains a rack 8 with sets of pairwise arranged transporting rollers 6, 7 which move the film 1 along a second U-shaped path. The tank 14 contains a supply of a fixing agent or fixer whose level is determined by an overflow pipe 10a connected to the evacuating pipe 11.

The tank 14 is followed by a third vessel or tank 15 for a rinse bath. The level of water in the tank 15 is determined by an overflow pipe 10b which is connected to the evacuating pipe 11. The tank 15 contains a rack 8a with sets of transporting rollers 16, 17 and a guide roller 18 which directs the film 1 into a dryer 19. The transporting rollers 16, 17 define for the film 1 a substantially U-shaped path similar to the path defined by the rollers 6, 7 on the rack 8 in the tank 14. The reference characters 12a and 12b denote pumps which re spectively serve to circulate fixer and water in the tanks 14 and 15. The contents of the tanks 14 and 15 can be evacuated in response to opening of normally closed 4 shutoff valves 13a, 13b. The dimensions of the tank 15 equal or approximate the dimensions of the tank 14.

The last pair of transporting rollers l6, 17 in the tank 15 serves to remove surplus water from the film I and the guide roller 18 is preferably heated by hot gaseous fluid in the dryer 19. The dryer 1) contains a rack 8b for sets of pairwise arranged transporting rollers 20 which advance the film 1 along an elongated down wardly extending path including one or more arcuate sections. The film which is advanced by the transporting rollers 20 moves counter to the direction of flow of a stream 21 of hot drying gas, preferably air, and the dried film is allowed to descend into an intercepting receptacle 22 located at the lower end of the dryer 19. The air stream 21 issues from the outlet of a suitable blower 119 and is heated by a thermostatically controlled heater 219 before it enters the dryer 19. The heated air stream 21 enters the dryer 19 by way of an opening 23 which is adjacent to the receptacle 22 and spent air is evacuated by way of two channels or ducts 24, 25 whose intake ends are adjacent to the upper end of the path along which the film 1 moves through the dryer 19. The discharge ends of the channels 24, 25 are connected to the suction inlet of the blower 119 so' that the stream 21 is circulated along a substantially closed path. A certain amount of fresh air is preferably added to the stream 21, for example, at the suction inlet of the blower 119. This insures that the moisture content of air which forms the stream 21 does not exceed a predetermined maximum value.

A heat exchanger 26 (see also FIG. 2) is installed in the channel 24 to withdraw heat from the respective portion of the air stream 21. As shown in FIG. 2, the heat exchanger 26 comprises a meandering coil 26b which is provided with disk-shaped fins or ribs 26a. If desired, the fins 2611 can be replaced by one or more helical fins preferably having large exposed surfaces to insure a satisfactory exchange of heat between unheated liquid in the coil 26b and hot air around the coil. The liquid in the coil 26b is assumed to be fresh water and the air in the channel 24 has a relatively high moisture content.

The intake end of the coil 26b is connected with a supply pipe 270 for fresh water which constitutes a source of unheated liquid. The pipe 270 is connected with the coil 26b by a flow regulating valve 27 which is preferably electromagnetically operated valve and opens in automatic response to introduction of a film 1 into the inlet of the tank 9. To this end, the processing apparatus 2 comprises a control means including a detector 28 (e.g., a normally open switch) which gener ates a signal to energize the electromagnet 27d of and to thus open the valve 27 in response to introduction of a film 1 into the nip of the advancing rolls 3, 4. As shown, the roll 3 constitutes a follower which is moved away from the roll 4 to thereby close the switch 28 as soon as the leader of a film 1 is introduced between the advancing rolls. The arrangement is preferably such that the valve 27 remains open for an interval of time which is required to transport a film through the processing apparatus 2. To this end, the conductor means 27b between the detector switch 28 and the electromagnet 27d of the valve 27 contains a time-delay relay 27c or the like which insures that the delay with which the valve 27 closes subsequent to opening of the switch 28 suffices to guarantee that the last film 1 of a series of films has reached the receptacle 22.

A second heat exchanger (similar to or different from the heat exchanger 26) can be installed in the duct 25 of the dryer 19, and such second heat exchanger can be connected in series or in parallel with the heat exchanger 26. It is further clear that the heat exchanger 26 can be installed in the duct 25.

The discharge end of the coil 26b is connected to the intake end of a coil forming part of a first additional heat exchanger 29 which is installed in the lower portion of the tank 9. The liquid which issues from the coil of the heat exchanger 29 enters the coil of a second additional heat exchanger 31 in the lower portion of the tank 14. The discharge end of the coil of the heat exchanger 31 admits water into the tank 15.

It will be noted that the transporting rolls move the films 1 downwardly through a first portion 19a of the dryer wherein the films are contacted by the ascending stream 2lof hot air, and that the heat exchanger 26 is installed in that portion (duct 24) of the dryer 19 which receives spent air from the portion 19a. This insures that unheated liquid flowing in the coil 26b withdraws heat from the air stream 21 after the air stream has completed the drying of films 1 in the dryer portion 19a.

The operation is as follows:

The cross-sectional area of the passage defined by the valve 27 for the flow of cold water from the source or pipe 270 into the coil 26b of the heat exchanger 26 is selected in such a way that the pipe 27a admits water at a rate which is needed for continuous operation of the processing apparatus 2. For example, when the apparatus 2 is to process 400 X-ray films per hour, the valve 27 can be set to admit into the coil 26b cold water at a rate of 2% liters per minute. The thus admitted stream of fresh water flows in the coil 26)) and is heated by moist air in the duct 24. As explained above, the coil 26b can discharge preheated water into a similar coil of a second heat exchanger in the duct 25 of the dryer 19. The fins 26a insure a highly satisfactory exchange of heat between water in the coil 26b and air in the duct 24. For example, the temperature of air which enters the duct 24 may approximate 45C. which is well above the temperature of fresh water in the pipe 27a. The temperature of water leaving the coil 26b depends on the rate of water flow through the heat exchanger 26; for example, the temperature of such water may be raised to 20C. or thereabout. The valve 27 is opened in automatic response to introduction of a film 1 into the nip of the advancing rolls 3, 4 because the roll 3 then closes the switch 28 which energizes the electromagnet 27d of the valve 27. As mentioned before, the relay 27c insures that the valve 27 remains open as long as at least one film 1 travels from the advancing rolls 3, 4 toward the intercepting receptacle 22. Thus, the valve 27 remains open continuously as long as the films 1 are fed at a rate which suffices to insure that a fresh film l is introduced into the nip of the advancing rolls 3, 4 before the preceeding film reaches the receptacle 22. Eventual heating of water in the coil 26b beyond a preferred average temperature does no harm; on the contrary, heated water in the coil 26b and in the coils of additional heat exchangers 29, 31 then prevents excessive cooling of processing liquids in the tanks 9, l4, and 15 when the apparatus 2 is at a standstill, for example, between the treatment of the last film 1 of a first series and treatment of the foremost film of the next series.

The temperature of water in the coil 26b and in the coils of additional heat exchangers 29, 31 reaches a desirable optimum value shortly after the valve 27 opens. The water remains at such optimum temperature regardless of whether the apparatus 2 is used intermittently or continuously. As mentioned above, eventual slight overheating of water in the heat exchangers does no harm and is even useful because slightly overheated water prevents an abrupt cooling of processing liquids in the tanks 9, l4 and 15. If the moisture content of hot air which leaves the dryer 19 through the duct 24 is very high, and especially if the flow of water in the coil 26b is counter to the direction of air flow in the duct 24, the external surface of the coil 26b and the exposed surfaces of the fins 26a are likely to be coated with condensate. This is desirable when the duct 24 does not discharge spent air into the atmosphere, i.e., when the outlet of the duct 24 is connected to the inlet of the blower 119 which admits the air stream 21 into the dryer 19 through the opening 23. Thus, the accumulation of condensate on parts of the heat exchanger 26 reduces the moisture content of air which flows in the duct 24. The condensate can be evacuated at the colder (intake) end of the coil 26b.

The difference between the temperature of water which leaves the coil 26b and the temperature of developing solution in the tank 9 is normally slight, e.g., in the range of a few degrees C. If the heat exchanger 29 is placed close to the outlet 9a of the tank 9, such small difference (in the range of one or more degrees C.) suf fices to insure that water flowing in the coil of the heat exchanger 29 maintains the developing solution which flows into the pump 12 at a temperature which is .constant or substantially constant, i.e., which differs from the desired optimum temperature of developing solution in the tank 9 by a substantially constant value. If the heating unit 30 is placed upstream of the heat exchanger 29, as considered in the direction of circulation of developing solution in the tank 9, the heating unit 30 can raise the temperature of liquid entering via inlet 9b to the optimum temperature for treatment of films in the tank 9. [t has been found that the heating unit 30 can be controlled with such a high degree of accuracy that the temperature of developing solution fluctuates negligibly and is normally within one or more tenths of lC. of the desired optimum temperature.

The temperature of water which flows in the coil of the heat exchanger 31 is only slightly less than the temperature of developing solution in the tank 9. Consequently, the heat exchanger 31 can raise the temperature of fixing bath in the tank 14 well above room temperature and such temperature is only slightly less than the temperature of liquid in the tank 9. The fixing bath in the tank 14 is further heated owing to exchange of heat with developing solution through the wall which separates the tanks 9 and 14. Such dual exchange of heat normally suffices to maintain the temperatures of liquid in the tank 14 within a narrow range without resorting to additional temperature regulating devices.

The discharge end of the coil in the heat exchanger 31 delivers water into the rinse bath in the tank 15. This insures that the temperature of liquid in the tank 15 is well above room temperature and is not appreciably below the temperature of developing solution in the tank 9. It has been found that such heating of rinse bath insures a highly satisfactory rinsing of films 1 in spite of the fact that the amounts of circulated water in the tank 15 are relatively small. For example, the pumps 12, 12a and 12b can be designed to circulate the respective liquids at the rate of 22 liters per minute. The rate of out- 7 flow of chemicals-containing water via pipe 11 equals the rate of admission of fresh water through the valve 27.

The processing apparatus 2 need not be connected to a hot water supply line and need not employ any valves for the mixing of hot and cold water. The operation is satisfactory regardless of whether the films 1 are fed continuously or intermittently.

It is clear that the developing apparatus of FIGS. 1 and 2 can be modified in a number of ways without departing from the spirit of the invention. For example, the heat exchanger 31 in the tank 14 can be omitted. Also, the heat exchanger 26 can be connected with the heat exchanger 31 and the heat exchanger 29 omitted if the heating unit is capable of maintaining the temperature of developing solution in the tank 9 within a desired range. The heating unit 30 can be omitted if the heat exchanger 29 is capable of preventing excessive fluctuations of liquid temperature in the tank 9 above or below an optimum temperature. For example, the heating unit 30 or the heat exchanger 29 will be omitted if the nature of films and/or the nature of developing solution is such that the temperature of liquid in the tank 9 can fluctuate within one or more degrees C.

The heat exchanger 26 constitutes but one form of means for withdrawing heat from gaseous fluid which leaves the dryer 19. For example, the frame of the dryer 19 can be assembled of pipes which are welded together and form one or more coils for fresh water. Also, the rack 8b and/or other parts (e.g., a heatinsulating jacket) of the dryer 19 can be provided with internal compartments for circulation of fresh water which is thereby heated prior to exchanging heat with liquid in the tank 9, 14 and/or 15. The rack 8b and/or the frame of the dryer 19 may be made hollow and can receive one or more heating coils for fresh water. As a rule, heat can be withdrawn from all such parts which are heated automatically when the processing apparatus is in use.

An important advantage 'of the heat exchanger 26 is that the stream of water entering the heat exchanger 29 is heated well above the temperature of fresh water in the pipe 27a. As mentioned before, the temperature of water leaving the coil 26b is normally only a few degrees C. below the desired optimum temperature of developing solution in the tank 9. This insures that the heat exchanger 29 withdraws from developing solution only such quantities of heat as are necessary to insure that the heating unit 30 can maintain the developing solution at the optimum temperature. Moreover, the liquid which leaves the heat exchanger 31 is sufficiently hot to insure an optimum heating of the rinse bath.

The detector 28 and relay 270 for the valve 27 can be replaced with other types of control means for regulating the rate of admission of fresh water in dependency on the number or combined surface area of films which are transported from the advancing rolls 3, 4 toward the receptacle 22. For example, such regulation can be effected by resorting to a control system of the type disclosed in German Pat. No. 1,237,789 which describes a pulse storing unit serving to receive and store a number of pulses and to erase the pulses at given intervals. Such storing unit can be used to control the valve 27 by receiving a number of pulses each of whcih corresponds to a film of a series offilms to be treated by maintaining the valve 27 in open position during erasure of successive pulses while the films pass through the tanks 9, 14,

8 l5 and dryer 19, and by closing the valve 27 upon completion of treatment of the last film.

FIG. 3 shows a portion of a second apparatus 102 wherein fresh liquid which has been heated in the coil of the heat exchanger 26 is discharged directly into the tank 15 (see the pipe 126). The outlet [00 of the pump 12b is not connected with the tank 15, i.e., the pump does not circulate the rinsing liquid in the tank 15 but supplies liquid to the additional heat exchanger 29 in the tank 9 (see the pipe 129). Such liquid thereupon flows through the heat exchanger 31 in the tank 14 and is discharged into the tank 15 via pipe 131.

The apparatus 102 exhibits the advantage that it further reduces the likelihood of penetration of chemicals into the supply pipe 270 for fresh water. Thus, when the valve 27 is open, fresh water can flow through the coil of the heat exchanger 26 and is discharged into the tank 15. Eventual return flow of water from the coil of the heat exchanger 26 into the pipe 27a cannot contaminate the source of fresh water since the liquid in the heat exchanger 26 is free of chemicals. Eventual leakage of the coil of the heat exchanger 26 can result in contact between fresh water and the gases in the duct 24; however, such gases are free of toxic ingredients.

Eventual leakage of coils forming part of the heat exchangers 29, 31 will result in contamination of liquid which is supplied by the outlet of the pump 12b. However, such chemicals will enter only the rinse bath in the tank 15. The contents of the tank 15 can flow only into the pump 12b and/or into the evacuating pipe 11. Thus, by the single expedient of discharging the contents of the coil of the heat exchanger 26 into the tank 15 and of filling the coils of the heat exchangers 29, 31 with liquid which is being withdrawn from the tank 15, the apparatus 102 insures that eventual leakage of the coil in the heat exchanger 26, 29 and/or 31 cannot result in contamination of the fresh water supply.

FIG. 4 shows a third apparatus 202 wherein the heat exchanger 31 is omitted, i.e., the coil of the heat exchanger 29 in the tank 9 delivers liquid directly into the tank 15 via pipe 229. If desired, and as shown by broken lines, the heat exchanger 31 can remain and the pipe 229 which discharges the contents of the coil of the heat exchanger 29 into the tank 15 contains a first valve 250 and the discharge end of the coil of the heat exchanger 31 contains a shutoff valve 251. The valve 250 is installed at the junction of the inlet of coil of the heat exchanger 31 with the pipe 229 and can be set to permit entry of liquid into the heat exchanger 31 or to seal the heat exchanger 31 from the pipe 229; in the latter instance, the shutoff valve 251 is also closed.

The apparatus 202 constitutes a simplification of the apparatus 2 or 102, especially if the heat exchanger 31 is omitted in its entirety. This heat exchanger is optional because the temperature of fixer in the tank 14 need not always be maintained within a narrow range, i.e., the requirements regarding the temperature of fixer are not as stringent as those regarding the temperature of liquid in the tank 9. 1f the heat exchanger 31 is omitted or sealed from the heat exchanger 29, the fixer in the tank 14 is heated by the partition (s) between the tank 14 and the tank 9 and/or 15.

It is further within the scope of the invention to utilize the pump 12b of FIG. 3 or FIG. 4 in the same way as the pump 12b of FIG. 1 (i.e., for circulation of rinse bath in the tank 15) and to provide an additional pump 9 which performs the function of the pump 12b in FIG. 3

or 4, namely to draw liquid from the tank 15 and to supply such liquid to the coil of the heat exchanger 29. Referring to FIG. 3, this would merely involve connecting the pipe 129 with the tank 15 below the upper surface of the rinse bath, installing an additional pump in the pipe 129, and connecting the outlet We of the pump 12b with the tank 15 in the same way as shown in FIG. 1.

Without further analysis, the foregoing will so fully reveal the gist of the present invention that others can, by applying current knowledge. readily adapt it for various applications without omitting features which fairly constitute essential characteristics of the generic and specific aspects of our contribution to the art and, therefore, such adaptations should and are intended to be comprehended within the meaning and range of equivalence of the claims.

What is claimed as new and desired to be protected by Letters Patent is set forth in the'appended claims.

1. in a processing apparatus for exposed films or analogous sheet or web-like carriers of photosensitive material, a combination comprising a series of vessels each containing a supply of a processing liquid; a dryer; means for circulating in said dryer a heated gaseous fluid; means for transporting carriers of photosensitive material through successive vessels and thereupon through said dryer; a source of unheated liquid; and a heat exchanger connectable with said source and installed in said dryer so that unheated liquid which is supplied by said source is heated in said heat exchanger, said heat exchanger having an outlet which discharges heated liquid into one of said vessels.

2. A combination as defined in claim 1, further comprising at least one additional heat exchanger which is .installed in a first vessel and means for circulating through said additional heat exchanger liquid which is being withdrawn from a second vessel.

3. A combination as defined in claim 2, wherein said second vessel is said one vessel and said additional heat exchanger has an outlet which discharges liquid back into said one vessel.

4. A combination as defined in claim 1, wherein said series includes a first, a second and a third vessel, said outlet of said heat exchanger being arranged to discharge heated liquid into said third vessel and further comprising an additional heat exchanger in one of said first and second vessels and means for conveying through said additional heat exchanger liquid which is being withdrawn from said third vessel.

5. A combination as defined in claim 4, wherein said additional heat exchanger has an outlet which discharges liquid into said third vessel.

6. A combination as defined in claim 4, wherein said additional heat exchanger is installed in said first vessel.

7. A combination as defined in claim 1, wherein said series includes a first, a second and a third vessel, said outlet of said heat exchanger being arranged to dis charge heated liquid into said third vessel and further comprising first and second additional heat exchangers connected in series with each other and respectively -installed in said first and second vessels, and means for supplying to one of said additional heat exchangers liquid which is being withdrawn from said third vessel, the other of said additional heat exchangers having an outlet with discharges liquid into said third vessel.

8. A combination as defined in claim 7, wherein said one additional heat exchanger is installed in saidfirst vessel.

9. A combination as defined in claim 1, further comprising means for circulating the liquid in at least one of said vessels.

10. A combination as defined in claim 1, wherein the liquid in said one vessel is a rinse bath.

a a m a 

1. In a processing apparatus for exposed films or analogous sheet - or web-like carriers of photosensitive material, a combination comprising a series of vessels each containing a supply of a processing liquid; a dryer; means for circulating in said dryer a heated gaseous fluid; means for transporting carriers of photosensitive material through successive vessels and thereupon through said dryeR; a source of unheated liquid; and a heat exchanger connectable with said source and installed in said dryer so that unheated liquid which is supplied by said source is heated in said heat exchanger, said heat exchanger having an outlet which discharges heated liquid into one of said vessels.
 2. A combination as defined in claim 1, further comprising at least one additional heat exchanger which is installed in a first vessel and means for circulating through said additional heat exchanger liquid which is being withdrawn from a second vessel.
 3. A combination as defined in claim 2, wherein said second vessel is said one vessel and said additional heat exchanger has an outlet which discharges liquid back into said one vessel.
 4. A combination as defined in claim 1, wherein said series includes a first, a second and a third vessel, said outlet of said heat exchanger being arranged to discharge heated liquid into said third vessel and further comprising an additional heat exchanger in one of said first and second vessels and means for conveying through said additional heat exchanger liquid which is being withdrawn from said third vessel.
 5. A combination as defined in claim 4, wherein said additional heat exchanger has an outlet which discharges liquid into said third vessel.
 6. A combination as defined in claim 4, wherein said additional heat exchanger is installed in said first vessel.
 7. A combination as defined in claim 1, wherein said series includes a first, a second and a third vessel, said outlet of said heat exchanger being arranged to discharge heated liquid into said third vessel and further comprising first and second additional heat exchangers connected in series with each other and respectively installed in said first and second vessels, and means for supplying to one of said additional heat exchangers liquid which is being withdrawn from said third vessel, the other of said additional heat exchangers having an outlet with discharges liquid into said third vessel.
 8. A combination as defined in claim 7, wherein said one additional heat exchanger is installed in said first vessel.
 9. A combination as defined in claim 1, further comprising means for circulating the liquid in at least one of said vessels.
 10. A combination as defined in claim 1, wherein the liquid in said one vessel is a rinse bath. 